After our showing of Zumanity at the New York New York Hotel and Casino we wandered over to the Bar at Time Square. It was not the best dueling piano bar I have ever been to, but we were entertained for almost 4 hours. Obviously the songs selected by the audience impact the vibe and some of the songs played weren't great for a piano bar with audience participation, but that wasn't the fault of the two teams of piano players they had working that night.
At one point they broke out the electric guitar and rocked out four or five songs.
We opted for the VIP seating (15 dollar cover) for a table right near the pianos. Our waitress was amazing and we never had to wait with an empty drink. Drink prices were reasonable for Vegas.